<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <title>Page Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>

</head>

<body>
    <div id='example-3'>

        <input type="checkbox" id="checkbox" v-model="checked">
        <label for="checkbox">{{ checked }}</label>
        <hr>

        <input type="checkbox" id="jack" value="Jack" v-model="checkedNames">
        <label for="jack">Jack</label>
        <input type="checkbox" id="john" value="John" v-model="checkedNames">
        <label for="john">John</label>
        <input type="checkbox" id="mike" value="Mike" v-model="checkedNames">
        <label for="mike">Mike</label>
        <br>
        <span>Checked names: {{ checkedNames }}</span>
    </div>
</body>
<script>
    var vm = new Vue({
        el: '#example-3',
        data: {
            checkedNames: [],
            checked: ''
        }
    })
</script>

</html>